#include "junix.h"
using namespace std;
struct Base
{
	virtual void  func(int arg = 1) {
		cout<<arg;
	}
};

struct Derived : public Base
{
	virtual void func(int arg = 2) {
		cout<<arg;
	}
};

int main(int argc, char **argv){
	Base *b = new Derived;
	b->func(); // 默认参数是多少？ 
}
